U.S. Pat. No. 4,284,274 to Boothe discloses an `Exercise Device` which utilizes a pair of bars, one each for the two persons exercising with the device and a tension member between the bars. The tension member is of such length so that, when two persons exercising are foot-to-foot and each person grasping his respective bar, one exerciser is supine and the other is bent forward to a toe-touching angle. With each pulling on his respective bar and a swivelling on the hip joints, the exercising persons alternate supine positions. Boothe ('274) provides exercise but requires the presence of two persons, making it inappropriate for the lone exerciser.
U.S. Pat. 5,125,649, to Fuller shows an exercise apparatus that uses a bar connected to another rigid structural member by elastic cords. Fuller's bar is a single bar without end bars, and the elastic cords are not adjustable in length. Fuller's bar is not intended to be used by itself, but only with other structural members.
A need exists for a portable, light weight exercise device that is multi-functional and can utilize several methods for the user to pit one set of muscles against another set of muscles, and usable by a single exerciser.